Technologies to examine deterioration of ropes used in elevators, cranes, and bridges are known. For example, a car and a counter weight of an elevator are hung in a hoistway with a plurality of main ropes. Wire ropes, resin-coated ropes, or the like are used for the main ropes. The wire rope includes a plurality of strands that is a plurality of twisted wires made of carbon steel or stainless steel. The wire rope is configured by twisting the plurality of strands around a rope core at predetermined pitches. Meanwhile, the resin-coated rope is a rope provided with resin-made coating on an outer periphery of a steel-made rope.
The main ropes are wound around a sheave of the elevator car, a sheave of the counter weight, and a sheave of the hoist. Deterioration such as abrasion and disconnection is caused in the strands and wires of the main ropes due to complex causes such as high frequent bending, tensile stress, and friction through the operation of the elevator. Therefore, examinations to confirm soundness of the main ropes are periodically performed in the operation of the elevator. As methods of examining the main ropes, for example, a method of taking the main ropes off the elevator device and performing an examination using a magnetic flow detector, and a method of visually examining the entire length of the main ropes by a maintenance worker while keeping the main ropes hung from the elevator device are known.
However, it has been difficult to examine the state of the ropes without depending on types of the ropes, in a state where the ropes are being used.